1. Field of the Invention
The present invention relates to goggles which are worn while, for example, playing sport, and which are used with a spectacles frame which is provided with positive or negative lenses.
2. Description of the Related Art
Conventionally, goggles are worn while playing sport, in order to protect the eyes from snow, dust, sunshine, and the like. The lenses of the goggles are manufactured first by forming an intermediate product that has spherical surfaces from glass material, and then shaping the intermediate product into a lens or lenses. The reason why this process is used is to facilitate manufacturing, reduce cost, and so on.
Some myopic or hyperopic people are not able to wear contact lenses since contact lenses are not good for their eyes. Such people are forced to wear the goggles with spectacles for correcting their myopia or hyperopia. Therefore, a frame in which lenses for correcting visual acuity are provided is mounted on the goggles as an inner frame. The inner frame is curved to some extent in accordance with the spherical surface of the goggles, and is attachably and detachably mounted at the side of the goggles, which is closer to the face of the user.
Generally, it is preferable that the optical axes of the right and left lenses of the spectacles for correcting visual acuity are respectively coaxial with the optical axes of the right and left eyes. However, it is difficult to accord the optical axes of the lenses with the optical axes of the eyes due to the movement of the pupils. Accordingly, the spectacles frame is shaped such that the lenses are parallel to the user's face when the spectacles are worn by the user.
However, since the above-mentioned inner frame is curved in accordance with the spherical surface of the goggles, the user can not see well. Accordingly, if the lenses for correcting myopia are provided in the inner frame, the axes of the lenses are decentered outwards by a predetermined distance, and if the lenses for correcting hyperopia are provided in the inner frame, the axes of the lenses are decentered inwards by a predetermined distance.
With this inner frame, when the pupils of the user are directed straight ahead, the user can obtain a good field of view. However, when the pupils are directed in the right and left directions, a good field of view cannot be obtained. For example, when the pupils are directed in the left direction, the center of a line which extends from the right eye passes through the right lens at a peripheral portion adjacent to the center of the inner frame, and the center of a line which extends from the left eye passes through the left lens at an outer peripheral portion. Then, the angles at which the lines, extending from the right and left eyes, are incident on the corresponding lens, are largely different. Accordingly, the inner frame cannot function well as an element for correcting visual acuity.